Bulldozer



June 28, 1960 E. B. LoNG BULLDOZER Filed Feb. 27, 1958 2 Sheets-Sheet 2 INVENTOR. E27-0N B. aA/6- QQ mi M* A TTKNEY United Statesl Patent' M Elton B. Long, Haskell, Iowa, asslgnor to J. I. Case Company, Racine, Wis., a corporation of Wisconsin Filed Feb. 27, 195s, ser.No.117,sss

s claims. (cl. :r1- 144) This invention relates in general to earth' moving equipment, such as scrapers, bulldozers and the like. More particularly, the invention relates to mounting means for adjustably securing the blade to the tractivc vehicle.

' Scraper blades for equipment of this type are conventionally mounted on the tractive vehicle so as to be capable of tilting from side to side in a vertical direction. In addition, the entire blade can also be bodily positioned in a vertical direction.

In order to be able to apply full down pressure on kthe blade, the means for vertically positioningthe blade should consist preferably of a hydraulic lift cylinder assembly on each side of the tractor which cylinders extend downwardly and are connected to the blade supporting frame. When the blade is to be tilted by other means on the tractor, a strain is usually imposed on the tractor frame, the lift cylinders, and blade mounting, and the blade has heretofore not been completely free to tilt or tip.

In accordance with the present invention, a blade mounting has been provided for a tractor which permits the blade to. be vertically positioned, 'preferably byphydraulic lift cylinders, with Ifull down pressure, and also permits the blade to be -freely tilted or tipped in any direction without imposing undue strain on the tractor- =frame and the lift cylinders and without causing any binding on the blade mounting frame members.

More specilically the invention provides a mounting of the above type havingan equalizing bar to which the vertical positioning means are attached and'also on which the blade is rotatably mounted. A

The invention contemplates a blade mounting of .the above character having means for vertically tilting 'the blade from end to end, which means also provides .for changing the pitch of the blade, the entire arrangement -resulting in a ilexible and efficient learth moving machine.

These and other objects and advantages vwilly-'appear A blade 18 is carried across the front end of the tractor on a pair of push arms 19, which extend along each side of the tractor and are swivelly secu-red by ball and socket connections C adjacent their rear ends on the trunnion blocks 21. Blocks 21 are bolted to the track sus- Y pension frame 13.' By providing swivel connections for the rear ends of the push arms, all twisting strains on the track yframe are eliminated, as will appear.

The push arms are fabricated from high-strength steelljf channels welded intobox sections'and close-coupled to drawings, in which:

Figure 1 is a side elevational view of a bulldozer em! bodying the present invention;

' Figure 2 is a fragmentary plan view of the blade mounting shown in Figure 1;

yFigure 3 is a fragmentary perspective View ofthe mounting shown in Figure 1, but on an enlarged scale;

Figure 4 is a sectional view taken on line 4-4 of Figure 2 and showing the connection of the equalizer bar tothe rear of the moldboard; Figure 5 is a diagrammatic View, on a showing the blade in the tilted position. l

Referring in greater detail to the drawings, Vthe invention has been shown for illustrative purposes as applied to a bulldozer 10 having a main frame structure 11 car ried on a pair of endless tracks 12 which are mounted on the track suspension frame 13. The operators platform 14 has hydraulic operating levers 15, 16 and 17 adjacent thereto. Levers 15 and 16 are arranged as a pair for purposes that will appear hereinafter.

pins 23. v j

llihe arms each have a bifurcated bracket 24 welded intermediate the length of their top side. Y Strut cylinder assemblies 25, 26 are pivotally attached adjacent' their rear ends to brackets 24 and extend forwardly and'up-v' Wardly therefrom. The double acting assemblies include cylinders 27 and piston rods 28, the latter of which are pivotally attached through Vthe bifurcated ends to the brackets 29 on the upper portion of the vblade by pins 30; By means of suitable hydraulic circuiting (not shown) pressure uid causes cylinder assembly 25 to be extended or retracted by movement of lever 15 in av forward or rearward direction, respectively. Cylinder assembly 26 is likewise extended or retracted by forward and rearward movement, respectively, of lever 16. By grouping levers 15 and 16 together, they may be moved simultaneously in either the same or opposite directions by one hand of the operator. The blade may thereby be piovted about pivot pins 23 to change the pitch thereof, or one end of the blade may be lowered andthe other en'd raised (or vice versa) to change the blade'tilt. In other words, either end of the blade may be dropped for cutting ditches, crowning roads and breaking-out hard ground. By moving levers forward or backward together the blade may be tipped yfore or aft to obtain the right rolling and scouring action for various types of soils.

Hydraulically operated means are also provided for bodily positioning the blade in a vertical directionwithout changing the'tilt thereof. This means should apply a force at both sides of the blade, that is at spaced locations along it-s length, and at the same time not interfere with the blade tilting or tipping action above de scribed. t Y

and disposed in a generally downwardly and forwardly extending position. A, cylinder bracket assembly 34 is secured to eachv side of the tractor main frame `bybolt means 35 and includes the yoke 36 in which the'cylinder 37 of the assembly .is pivotally secured. s The piston-rod 38 of the cylinder -assembly is bifurcated at its lower end. f x

An lequalizer member in the form of an equalizer bar 40 is swivelly connected to the rear' side of the blade. This swivel connection includes a ring 41 welded to the rear side of the blade, which ring has a'flaredopening 42 therethrough which converges in a rearward direction. A plate 43 has a beveled ange 44 which complements the opening 42 and is rotatably held captive therein. The bar 40 is welded directly to plate 43, the latter presenting a large thrust-delivering:bearing surface to the blade.

` The bar 40 has `a rearwardly facing bifurcated portion 5 alignment with arm pins 23 in order that the bladecan" 46 at each of its ends, which portions form a universal connection with the lower ends of pistons 38 by means Y of blocks 47 and pins 48 and 49.

A diagonal brace 51 is secured at its rear end to the inner side of each of arms 19, 20 as at 52. The brace is pivotally secured atl its front end to the blade on a horizontal axis defined by pivot pins 53. Pins 53 are n' Patented .lane 215.1960

tip"withoutibindingfaction of the brace. The braces serve to prevent lateral swinging of the blade and arms with respect to the tractor. However, they do not in-V terfererwith the tilting of the blade in its vertical plane because of the ball and socket connectionof theV rear ends of the push arms 19 to the tractor frame. These connections permit the push bars'to rotate slightly or tilt about their own longitudinal axes as they are moved vertically and consequently swung in an arcuate movement about the longitudinal pivot axis of theblade. This freedom of push bar movement prevents any twisting strains on the tractor frame'or blade mounting members whenv the blade is tilted.

By means of this equalizer bar 40, the cylinder assemblies 32, 33 are connected 'with the blade at laterally spaced locations and at opposite sides ofthe tractor frame, while the lifting force or alternatively the 'reaction on the tractor frame resulting from any down pressure on the blade is symmetrically distributed on the tractor frame without any tendency toward distortion of the same. This distortion has been a common difiiculty in past constructions when the rams were connected at spaced points directly to the blade, in that if one ram bottoms when the blade is tilted, the other exerts the entire upward reaction on one side only of the frame, resulting in serious straining and distortionl thereof. This situation would arise, forexample, when attempting to reduce a crowned surface, so that the end of the blade which happened to be the lower end was unsupported, while substantial .downy pressure was being exerted on the higher end.

The blade may be made toswivel on the bar by the actuation of the strut cylinder assemblies 25, 26 in opposite directions to thereby provide blade tilt, the bar in the meantime being held by the cylinder assemblies 32, 33. Alternatively, the assemblies 32, 33 maybe actu-V ated by lever 17 simultaneously with the strut cylinders to enable the blade to be tilted to any desired angle while also raising or lowering the entire blade. Lever i7 is connected by suitable hydraulic circuitry (not shown) to extend or retract cylinder assemblies 32 and 33 together.

The blade may also be pitched fore and aft by moving levers 15 and 16 together in a fore or aft direction, whichcauses cylinder assemblies 25, 26 to extend and retract together, respectively. In this instance the blade pivots about pins 23 and cylinder assemblies 32, 32a-swing unrestrictingly with the blade. The blade as shown by the broken lines in Figure 1 has been moved to a forwardly pitched position by extending both of the cylinders 25l and 26.

The lift cylinders being connected to the equalizing b ar and positioned in a downwardly extending direction can apply full down pressure directly on the blade without the use of intermediate bellfcranks or other linkage. The equalizer bar is center-pivoted to the rear of the moldboard, and enablesV the blade to be tilted and; tipped freely in any directionhwithout any strain on the lift cylinders or frame members.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. A bulldozer construction for a tractor comprising, apair of push armseach adapted to be pivotally attached to said tractor and to extend forwardly along one side thereof, a blade extending acrossthefront of said tractor and pivotally connected to said arms for fore and aft tipping, a pair of extensible means each pivotally connected between one of said arms and said blade, av pair of hydraulic cylinder assemblies, each pivotally connected on one side of saidtractor andA extending generally downwar'dly and forwardly'therefrom, an equalizer bar extendingin a direction generally parallel 'to said blade andV pivotally-- connected intermediateV its lentgh tovsaid bladeSf 1gi assemblies; being connected at their forward.

ends to the ends of said bar for vertically positioning the latter, both of said extensible means being adapted to be changed in length together in the same direction for tipping the blade to change its pitch, and said extensible means also being adapted to be extended and contracted in directions opposite to one another to tilt said blade about its pivotal connection to said bar.

2. A bulldozer construction for a tractor comprising, a pair of push arms each adapted to be pivotally attached at its rear end to said tractor .and to extend forwardly along one side thereof, a blade extending across the front of said tractor and pivotally connected adjacent its lower side to the front ends of said arms for fore and aft tipping relative tosaid arms, a pair of extensible means each pivotally connected between one of said arms and said blade, a pair of hydraulic cylinder assemblies, each pivotally connected to one side of said tractor and extending generally downwardly and forwardly therefrom, an equalizer bar extending in a direction generally parallel to said blade and pivotally connected intermediate its length to said blade, said hydraulic cylinder assemblies being swivelly connected at their forward ends to the ends of said bar for vertically positioning the latter, both of said extensible means being adapted to be lengthened and shortenedv together for tipping the blade to change its pitch, and said extensible means also being adapted to be independently and alternately extended and contracted in directions opposite to one another to tilt said blade about its pivotal connection to said bar.

3. In a bulldozer, the combination comprising, a trac# tor, a pair of push arms each pivotally attached at its rear end to said tractor and extending forwardly along one side thereof, a blade extending across the front `of said tractor and pivotally connected adjacent its lower side'V to the `front ends of said arms for fore and aft tipping relative to said arms, a pair of extensible means each pivotally connected between one of said arms and said blade, a pair of hydraulic cylinder assemblies, each pivotally connected to one side of said ltractor and extending generally downwardly and forwardly therefrom, an equalizer bar pivotally connected intermediate its length to said blade, said hydraulic cylinder assemblies being swivelly connected at their forward ends to the ends of said bar for vertically positioning the latter, both of said extensible means being adapted to be lengthened and shortened together for tipping the blade to change its pitch, said extensible means also being adapted to be independently and alternately extended and contracted in directions opposite to one another to tilt said blade, about its pivotal connection to said bar.

4. Ina bulldozer, the combination comprising, a tractor, a pair of push arms each pivotally attached at its rear end to said tractor andV extending forwardly along one side thereof, a blade extending across the front of said tractorf and pivotally connected adjacent its lower side to the front ends of said arms for fore andaft tipping relative to said arms, a pair of hydraulic extensible struts each pivotally connected between one of said arms and said blade, a pair of hydraulic cylinder assemblies, each pivotally connected to one side ofv said tractor and extending generally downwardly and forwardly therefrom, an equalizer bar pivotally connected intermediate its length to a central portion of said blade, said hydraulic cylinder assemblies being swivelly connected at their forward ends to the ends of said bar for vertically positioning the latter, both of said struts being adapted to be lengthened andjshortened together for tipping the blade to change its pitch, said struts also being adapted to beV independently and alternately extended and contracted in directions opposite to one another to tilt said blade about itspivotal connection to said bar.

push arms swivelly connected: adjacent: Vtheir rear1 ends.

`M"\bodily raising said blade, both of said tipping means beto said grader and extending forwardly thereof, said arms terminating in laterally spaced front ends, a transverse blade pivoted to the front ends of said arms for tipping movement lengthwise of the direction of grader travel, means at each vend of said blade and -arms to cause said tipping movement, a transversely positioned equalizer member pivotally connected about a longitudinal axis to said blade, said axis being located intermediate the length of said equalizer member, and a vertical positioning means connected between each side of said grader and said member for bodily raising said blade, both of said tipping means being simultaneously changeable in length either in the same direction to effeet said tipping movement or in opposite directions for tilting the blade vertically about its pivotal connection tipping movement, a generally horirzontally disposedV equalizer bar pivotally connected centrally of its length to said blade, and a pair of hydrauliccylinder assemblies, each pivotally mounted on one side of said grader and attached to the'corresponding end of said bar for ing simultaneously changeable in length either in the same direction to effect said tipping movement or in opposite directions for tilting the blade vertically about its pivotal connection to said equalizer bar.

7.- An adjustable blade mounting for a push grader comprising, a pair of transversely spaced push arms adapted to be swivelly connected adjacent their rear ends to said grader and to extend forwardly thereof, a transverse blade pivoted adjacent its lower edge to the front ends of said 4arms for tipping movement lengthwise of the direction of grader travel, a pair of fluid pressure extensible struts, each between said blade and one of said arms to cause said tipping movement, a horizontally disposed equalizer bar pivotally connected centrally of its length to said blade, and a pair of hydraulic cylinder assemblies, each pivotally mounted on one side of said grader and extending downwardly and `forwardly and having its forward end connected to the corresponding end of said bar for bodily raising said lblade, both of said struts being simultaneously changeable in length either in the same direction to elect said tipping movement or in opposite directions for tilting the blade vertically about its pivotal connection to said equalizer bar.

8. In combination, a tractor, a pair of pusher arms, each independently and swivelly mounted adjacent its rear end to one side of said tractor, said arms terminating in laterally spaced front ends, an earth moving blade pivotally secured on a transverse axis to the front ends of said arms, extensible means on each arm for tipping said blade about said axis, a transversely positioned equalizer member pivotally attached about a longitudinalV axis to said blade, said axis being located intermediate the length of said equalizer member, and a pair of power actuated devices, each pivotally connected between one side of said tractor and the respective end of said member for -bodily raising said blade and applying down pressure thereto, said extensible means both being adapted to be changed in length either in the same direction t-o vary the blade pitch or in opposite directions to tilt said blade relative to said equalizer member.

References Cited in the file of this patent UNITED STATES PATENTS 2,160,595 Le Bleu May30, 1939 2,224,725 Felt Dec. 10, 1940 2,239,943 Sword Apr. 29,- 1941 2,408,268 Peterson et al. Sept. 2A, 1946 2,636,289 Pryor Apr. 28, 1953 2,678,508 Reuter et al. May 18, 1954 2,687,586 Dickinson Aug. 31, 1954 2,749,630 Nave June 12, 1956 2,766,536 Perkins Oct. 16, 1956 2,817,168 Mullin Dec. 24, 1957 2,839,849 Christensen et al. June 24, 1958 

